When tools are used in a manufacturing or service environment, it is important that tools be returned to a storage unit, such as a tool box, after use. Employers typically perform a manual inventory check of the tool box to minimize or eliminate the problem of misplacement or theft of expensive tools. Companies can conduct random audits of employee's toolbox to prevent theft and monitor tool location.
Some industries have high standards for inventory control of tools, for preventing incidents of leaving tools in the workplace environment where they could cause severe damages. For the aerospace industry, it is important to ensure that no tools are accidentally left behind in an aircraft or missile being manufactured, assembled or repaired. The Aerospace Industries Association even establishes a standard called National Aerospace Standard including recommended procedures, personnel management and operations to reduce foreign object damage (FOD) to aerospace products. FOD is defined as any object not structurally part of the aircraft. The most common foreign objects found are nuts, bolts, safety wire, and hand tools. Inventory control over tools is critical to prevent tools from being left in an aircraft.
Some toolboxes includes build-in inventory determination features to track inventory conditions of tools stored in those toolboxes. For example, some toolboxes dispose contact sensors, magnetic sensors or infrared sensors in or next to each tool storage locations, to detect whether a tool is placed in each tool storage location. Based on signals generated by the sensors, the toolboxes are able to determine whether any tools are missing. While this type of inventory check may be useful to some extents, it suffers from various drawbacks. For instance, if a sensor detects that something is occupying a storage location, the toolbox will determine that no tool is missing from that storage location. However, the toolbox does not know whether the right kind of tool is indeed placed back in the toolbox or it is just some objects placed in the storage location to cheat the system. Furthermore, disposing sensors for numerous storage locations in a toolbox is tedious and costly, and the large number of sensors is prone to damages or malfunctions which will produce false negative or positive alarms.
Accordingly, there is a need for an effective inventory control system that that could assist tracking and accounting for usage of tools and whether they are properly put back after usage. There is also a need for an inventory control system which knows exactly what tool is removed or returned to a tool box. Furthermore, as multiple workers may have access to the same tool box, there is another need for an inventory control system that can track a user and his or her usage of tools, to determine responsibilities for any tool loss or misplacement.
This disclosure describes various embodiments of highly automated inventory control systems that utilize unique machine imaging and methodology for identifying an inventory condition in the storage unit. Illustrative features include the ability to process complex image data with efficient utilization of system resources, autonomous image and camera calibrations, identification of characteristics of tools from image data, adaptive timing for capturing inventory images, efficient generation of reference data for checking inventory status, autonomous compensation of image quality, etc.
An exemplary inventory control system includes at least one storage drawer, each storage drawer including a plurality of storage locations for storing objects; a data storage device storing reference data for each storage drawer, wherein the reference data includes, for each region of interest corresponding to each respective storage drawer, at least one of a reference image signature representing attributes of the region of interest when a stored object is present, and a reference image signature representing attributes of the region of interest when the stored object is not present; and a data processor. The data processor is configured to derive an image signature representing attributes of a region of interest corresponding to a drawer using a captured image of the drawer; and determine an inventory condition of the drawer according to the stored reference data corresponding to the region of interest and the derived image signature representing attributes of the captured image of the region of interest. The captured image of a drawer may be an image of the entire drawer or a partial image of the drawer.
In one aspect, the image signature is derived based on a pixel number distribution of an image relative to preset image attributes. The data processor may generate the image signature of the image by accessing data including the pixel number distribution relative to preset image attributes; identifying a group of pixels sharing a set of common image attributes based on a number of pixels sharing the common image attributes; identifying one or more groups of pixels sharing a different set of common image attributes based on a number of pixels sharing the different set of common image attributes; and generating the image signature based on the common image attributes of the identified pixel groups.
Each storage location may be configured to store a pre-designated tool, and each storage location may be associated with one or more pre-defined regions of interest. In one embodiment, the data processor determines an inventory condition of the pre-designated tool of a respective storage location based on a correlation of the image signature of each region of interest associated with the storage location, and the reference image signature corresponding to each region of interest associated with the storage location.
A method for using in an inventory control system for determining an inventory condition of objects stored in the system, the system comprising at least one storage drawer for storing objects, a data storage device storing reference data for each storage drawer, wherein the reference data includes, for each region of interest corresponding to each respective storage drawer, at least one of a reference image signature representing attributes of the region of interest when a stored object is present, and a reference image signature representing attributes of the region of interest when the stored object is not present; the method comprising: capturing an image of a drawer; deriving an image signature representing attributes of a region of interest corresponding to a drawer; and determining an inventory condition of the drawer according to the stored reference data corresponding to the region of interest in connection with the drawer and the derived image signature representing attributes of the captured image of the region of interest corresponding to the storage drawer.
According to another embodiment, an inventory control system according to this disclosure includes at least one storage drawer, each storage drawer including a foam layer forming a plurality of storage locations for storing objects, wherein each storage location is configured to store a pre-designated object and each storage location is formed by a cutout of the foam layer corresponding an object stored in the storage location; an image sensing device configured to capture an image of one of the storage drawers; a data storage system storing reference data corresponding to each storage drawer, wherein the reference data includes information of one or more pre-defined regions of interest corresponding to each storage location in the drawer, and objects stored in each storage location in the drawer; and a data processor. The data processor is configured to access the captured image of the drawer; access the reference data corresponding to the drawer; determine an inventory condition of the drawer based on the stored reference data corresponding to the drawer and the captured image of the storage drawer. The reference data is adapted from a data file based on which cutouts of the foam layer are created. In one aspect, the data processor imports the data file based on which cutouts of the foam layer are created, and derives the reference data from (change to based on) the data file.
According to still another embodiment, a novel method is proposed for preparing reference data for use in an inventory control system for determining an inventory condition of objects stored in the system. The system includes at least one storage drawer, each storage drawer including a foam layer forming a plurality of storage locations for storing objects, wherein each storage location is configured to store a pre-designated object and each storage location is formed by a cutout of the foam layer corresponding an object stored in the storage location, the system determines the inventory condition of a respective drawer based on a captured image of the respective drawer and the reference data. The method comprises: for each respective drawer, importing, from a database, a data file based on which cutouts of the foam layer for the respective drawer are created, wherein the data files includes positional information of each cutout in the respective drawer; and using a data processing device to create a data structure specifying positional information of each cutout in each respective drawer and at least one region of interest corresponding to each cutout, according to the imported data file.
Methods and systems described herein may be implemented using one or more computer systems and/or appropriate software.
It is understood that embodiments, steps and/or features described herein can be performed, utilized, implemented and/or practiced either individually or in combination with one or more other steps, embodiments and/or features.
Additional advantages and novel features of the present disclosure will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the present disclosure. The embodiments shown and described provide an illustration of the best mode contemplated for carrying out the present disclosure. The disclosure is capable of modifications in various obvious respects, all without departing from the spirit and scope thereof. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. The advantages of the present disclosure may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.